1. Technical Field
The present invention relates generally to an optical system, and more particularly to a compact optical image capturing system for an electronic device.
2. Description of Related Art
In recent years, with the rise of portable electronic devices having camera functionalities, the demand for an optical image capturing system is raised gradually. The image sensing device of the ordinary photographing camera is commonly selected from charge coupled device (CCD) or complementary metal-oxide semiconductor sensor (CMOS Sensor). In addition, as advanced semiconductor manufacturing technology enables the minimization of the pixel size of the image sensing device, the development of the optical image capturing system towards the field of high pixels. Therefore, the requirement for high imaging quality is rapidly raised.
The conventional optical system of the portable electronic device usually has two lenses. However, the optical system is asked to take pictures in a dark environment, or is asked to provide a wide view angle to satisfy the requirement for taking selfies through the front camera of a portable phone. In other words, the optical system is asked to have a large aperture. However, an optical system having large aperture usually generates aberrations, which causes poor imaging quality at peripheral portions, and also increases the difficulty of manufacturing such an optical system. In addition, an optical system with a wide view angle usually has higher distortion while imaging. The conventional optical system could not provide high optical performance as required.
It is an important issue to increase the amount of light entering the lens, and to widen the view angle of an optical image capturing system. In addition, the modern lens is asked not only to contain more total pixels, to provide higher image quality, but also to balance the requirements for a miniature optical image capturing system.